Ground Recovery Heat Pumps

This still seems to be a very expensive option in New Zealand. The technology is proven overseas but the true costs of setting this up does not make this a viable option for most domestic consumers, yet. We have yet to see a system that is delivering a high performance level and at a reasonable capital cost.

Those considering these systems need to be careful about how much land area is really required to create a proper capture grid, the possible cooling effects that a grid may have on garden areas, how deep the grid needs to be laid (a minimum of 1.5 metres), or the number and cost of bore holes as an alternative, and the extra cost of pumping water through these systems.

Indications are that these systems are better suited to the consistently cold (sub-zero) climates of Continental Europe and North America and may not be as effective in New Zealand's temperate and highly variable climate. A cold area such as Queenstown, for instance, has an average mean daily temperature in June / July of 4-4.5°C, not -10°C plus as in many continental areas.

There are some individuals pursuing this and we will continue to watch developments carefully.